(Brussels, Belgium) Microsoft Corp. said Tuesday software developers would no longer need to pay or license technology it provides to help one computer run multiple operating systems at the same time.

It said it would provide access to a "virtualization" format on an open source basis, saying this was the best way to get the broadest audience for its own specifications. The technology makes it easier for users to access programs or look at documents made by non-Microsoft vendors.

Demand from customers _ particularly in the government sector _ who use open-source servers such as Linux was one of the main reasons for it to move toward open-source standards, said Microsoft spokesman Tom Brookes.

He said it was not connected to Microsoft's rows with EU regulators over supplying interoperability information to rivals.

From Tuesday, the company will no longer ask developers to sign a license agreement. They are already offered the standard without cost.

Microsoft cited a study from research group International Data Corp. saying it expected about 500,000 servers equipped with the virtual hard-disk technology would enter the marketplace this year, up from roughly zero just three years ago. The study showed that by 2009, about 1.2 billion machines should be equipped with the technology.